still low voltage problem

[alfamarty]

o.k. this problem is getting wierder--I've cleaned every ground and connection I can find (86 gtv6) when the car is cold it has plenty of power and I can turn on /off electrical accesorys and they work just fine -but when it heats up even before the cooling fans kick on it goes to about 1/4 of the throttle and then it starts to bog down?? if I turn on the heater fan or use the windows it loses power completely--the battery and the altenator seem to be fine I get over 14 v coming off the altenator tho I haven't been able to check how many amps it's putting out----- what does the computer/relays? do that uses power when the engine heats up.if I go downhill for long enough when it's acting up and it cools sufficiently it goes like arocket again. anyone got any ideas?

[papajam]

It's my understanding that the L-Jet system is quite suseptible to low voltage resulting in all sorts of drivability/no start problems. Even though there's 14v at the alternator output, it may not be getting to the rest of the car. Try this. Verify 14v at the alt output terminal with the engine hot. Then, while keeping the voltmeter positive lead on the alt output, put the negative voltmeter lead on battery positive. Not on the cable but on the post itself. If the voltmeter reads anything other than zero, there's a voltage drop in the power distribution circuit somewhere. If the alt doesn't put out 14v when hot or the voltage drop test is OK, I'd have the alternator load tested.
Another possibility is a failing fuel supply pump.

[alfamarty]

thanks Jim I'll try the voltage drop test